Figure 3: Diffuse shaded image using Equation 1 with k_d = 1 and k_a = 0. Black shaded regions hide details, especially in the small claws; edge lines could not be seen if added. Highlights and fine details are lost in the white shaded regions.

  

Figure 4: Image with only highlights and edges. The edge lines provide divisions between object pieces and the highlights convey the direction of the light. Some shape information is lost, especially in the regions of high curvature of the object pieces. However, these highlights and edges could not be added to Figure 3 because the highlights would be invisible in the light regions and the silhouettes would be invisible in the dark regions.

  

Figure 5: Phong shaded image with edge lines and k_d = 0.5 and k_a = 0.1. Like Figure 3, details are lost in the dark grey regions, especially in the small claws, where they are colored the constant shade of k_d k_a regardless of surface orientation. However, edge lines and highlights provide shape information that was gained in Figure 4, but couldn't be added to Figure 3.

  

Figure 6: Approximately constant luminance tone rendering. Edge lines and highlights are clearly noticeable. Unlike Figures 3 and 5 some details in shaded regions, like the small claws, are visible. The lack of luminance shift makes these changes subtle.

  

Figure 7: Luminance/hue tone rendering. This image combines the luminance shift of Figure 3 and the hue shift of Figure 6. Edge lines, highlights, fine details in the dark shaded regions such as the small claws, as well as details in the high luminance regions are all visible. In addition, shape details are apparent unlike Figure 4 where the object appears flat. In this figure, the variables of Equation 2 and Equation 3 are: b = 0.4, y = 0.4, $\alpha$ = 0.2, and $\beta$ = 0.6.

  

Figure 8: Luminance/hue tone rendering, similar to Figure 7 except b = 0.55, y = 0.3, $\alpha$ = 0.25, and $\beta$ = 0.5. The different values of b and y determine the strength of the overall temperature shift, where as $\alpha$ and $\beta$ determine the prominence of the object color, and the strength of the luminance shift.

  

Figure 9: Top: Colored Phong-shaded spheres with edge lines and highlights. Bottom: Colored spheres shaded with hue and luminance shift, including edge lines and highlights. Note: In the first Phong shaded sphere (violet), the edge lines disappear, but are visible in the corresponding hue and luminance shaded violet sphere. In the last Phong shaded sphere (white), the highlight vanishes, but is noticed in the corresponding hue and luminance shaded white sphere below it. The spheres in the second row also retain their ``color name''.

  

Figure 10: Left to Right: a) Phong shaded object. b) New metal-shaded object without edge lines. c) New metal-shaded object with edge lines. d) New metal-shaded object with a cool-to-warm shift.

  

Figure 11: Left to Right: a) Phong model for colored object. b) New shading model with highlights, cool-to-warm hue shift, and without edge lines. c) New model using edge lines, highlights, and cool-to-warm hue shift. d) Approximation using conventional Phong shading, two colored lights, and edge lines.

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